Finally, an easy-to-use media reactor that is both economical and durable!

Great for use with GFO (granular ferrous oxide), activated carbon, biological media or most types of aquarium filter media.

Features

Heavy-duty, durable construction

Clear housing for easy visual inspection

High-capacity cartridge

Quick disconnect fittings for easy servicing

Ball valve for precise flow adjustment

Fitting allows for quick-disconnect with any Cobalt MJ powerhead

Wall bracket for installation inside aquarium stand

Filter wrench included

*Filter media sold separately
**Not designed for BioPellets

Cobalt MJ1200 Powerhead/Pump Information

The Original MJ multi-use submersible pump and power head is built to perform and last under the harshest conditions. Ideal for wave makers, protein skimmers, calcium reactors, nano aquariums, under gravel filters and hydroponic applications.

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Simple and Effective

by
Kyle Stewart

Excellent!

Posted: 8/26/2014 from Claremont, California

5.05

Experience Level:
Intermediate

Comments:I have the MD double media reactor mounted inside my aquarium stand. Installation was fairly straight-forward if you watch the video. I run AquaMaxx Carbon in the first reactor and GFO inside the second. The flow rate is a bit difficult to control, but my water is crystal clear and algae growth has decreased, so I know they are doing their jobs. These units saved me a lot of space and have already proven to be more effective than using filter media bags. Maintenance is easy; I swap out media once per month.

Horrible

by
KAREEM PHILLIPS

Unsatisfactory

Posted: 10/31/2013 from SUFFOLK, VA UNITED STATES

0.55

Experience Level:
Intermediate

Comments:This filter clogs very easily. In my opinion the pump that comes with it does not have enough pressure. The instructions could be better and you may have to buy extra hose. I'm returning the one I bought.

Dual reactor

by
JOHN KELLER

Great

Posted: 7/14/2013 from KENNEWICK, WA UNITED STATES

4.05

Experience Level:
Intermediate

Comments:Product was well packed and upon inspection seems really well made. At first start up there were 0 leaks a little tricky getting the flow valve set correctly but once I got that all seems to be ok. Running seachem carbon in the first and seachem phosgaurd in the sencond. Its only been running for 2 days so time will tell.

Marine depot GFO media reactor

by
CURTIS HOWARD

Unsatisfactory

Posted: 6/24/2013 from DIAMOND BAR, CA UNITED STATES

0.55

Experience Level:
Intermediate

Comments:This reactor did not meet my expectations. The biggest issue was the GFO media was so light that their was no weight to keep the pads in place so the pads lift and mix with the media. If you put to much media in the chamber their is no flow to keep the media moving so everything settles to the bottom. I'm now using another reactor and all is well.

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